Angelique Kerber's run at the BNP Paribas Open came to an end in the last 16, while Karolina Pliskova booked a quarter-final berth.
Set to reclaim the world number one ranking from Serena Williams, second seed Kerber did not look like a player poised to return to the WTA summit after she was bundled out by fellow seed Elena Vesnina.
The two-time grand-slam champion exited Indian Wells in straight sets on Tuesday.
Czech third seed Pliskova had no such trouble after Swiss opponent Timea Bacsinszky retired in the first set and will face Garbiñe Muguruza in the next round after the Spanish seventh seed beat Elina Svitolina in three sets.
American veteran Venus Williams also progressed to the last eight of the WTA Premier tournament.
Kerber's 2017 woes continue
The 29-year-old Kerber took the WTA circuit by storm last year, winning the Australian and US Opens.
She also reached the Wimbledon decider, while claiming silver at the Rio Olympics.
However, 2017 has not gone according to plan for Kerber as she looks a shadow of the major-winning player.
Kerber is 9-6 following her loss to Vesnina and she is yet to contest a final this year.